import asyncio
import base64
import time
from abc import ABC, abstractmethod
from typing import Callable, Dict, Any, List, Optional, Awaitable
import os
from playwright.async_api import async_playwright, Page, Browser, Error
from io import BytesIO
from PIL import Image, ImageDraw, ImageFont
from pathlib import Path
from playwright.async_api import ProxySettings
from pydantic import BaseModel
import hashlib
import json
import uuid
from playwright_stealth import stealth_async

class AsyncCrawlResponse(BaseModel):
    html: str
    response_headers: Dict[str, str]
    status_code: int
    screenshot: Optional[str] = None
    get_delayed_content: Optional[Callable[[Optional[float]], Awaitable[str]]] = None

    class Config:
        arbitrary_types_allowed = True

class AsyncCrawlerStrategy(ABC):
    @abstractmethod
    async def crawl(self, url: str, **kwargs) -> AsyncCrawlResponse:
        pass
    
    @abstractmethod
    async def crawl_many(self, urls: List[str], **kwargs) -> List[AsyncCrawlResponse]:
        pass
    
    @abstractmethod
    async def take_screenshot(self, url: str) -> str:
        pass
    
    @abstractmethod
    def update_user_agent(self, user_agent: str):
        pass
    
    @abstractmethod
    def set_hook(self, hook_type: str, hook: Callable):
        pass

class AsyncPlaywrightCrawlerStrategy(AsyncCrawlerStrategy):
    def __init__(self, use_cached_html=False, js_code=None, **kwargs):
        self.use_cached_html = use_cached_html
        self.user_agent = kwargs.get(
            "user_agent",
            "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 "
            "(KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36"
        )
        self.proxy = kwargs.get("proxy")
        self.headless = kwargs.get("headless", True)
        self.browser_type = kwargs.get("browser_type", "chromium")
        self.headers = kwargs.get("headers", {})
        self.sessions = {}
        self.session_ttl = 1800 
        self.js_code = js_code
        self.verbose = kwargs.get("verbose", False)
        self.playwright = None
        self.browser = None
        self.hooks = {
            'on_browser_created': None,
            'on_user_agent_updated': None,
            'on_execution_started': None,
            'before_goto': None,
            'after_goto': None,
            'before_return_html': None,
            'before_retrieve_html': None
        }

    async def __aenter__(self):
        await self.start()
        return self

    async def __aexit__(self, exc_type, exc_val, exc_tb):
        await self.close()

    async def start(self):
        if self.playwright is None:
            self.playwright = await async_playwright().start()
        if self.browser is None:
            browser_args = {
                "headless": self.headless,
                "args": [
                    "--disable-gpu",
                    "--no-sandbox",
                    "--disable-dev-shm-usage",
                    "--disable-blink-features=AutomationControlled",
                    "--disable-infobars",
                    "--window-position=0,0",
                    "--ignore-certificate-errors",
                    "--ignore-certificate-errors-spki-list",
                    # "--headless=new",  # Use the new headless mode
                ]
            }
            
            # Add proxy settings if a proxy is specified
            if self.proxy:
                proxy_settings = ProxySettings(server=self.proxy)
                browser_args["proxy"] = proxy_settings
                
            # Select the appropriate browser based on the browser_type
            if self.browser_type == "firefox":
                self.browser = await self.playwright.firefox.launch(**browser_args)
            elif self.browser_type == "webkit":
                self.browser = await self.playwright.webkit.launch(**browser_args)
            else:
                self.browser = await self.playwright.chromium.launch(**browser_args)

            await self.execute_hook('on_browser_created', self.browser)

    async def close(self):
        if self.browser:
            await self.browser.close()
            self.browser = None
        if self.playwright:
            await self.playwright.stop()
            self.playwright = None

    def __del__(self):
        if self.browser or self.playwright:
            asyncio.get_event_loop().run_until_complete(self.close())

    def set_hook(self, hook_type: str, hook: Callable):
        if hook_type in self.hooks:
            self.hooks[hook_type] = hook
        else:
            raise ValueError(f"Invalid hook type: {hook_type}")

    async def execute_hook(self, hook_type: str, *args):
        hook = self.hooks.get(hook_type)
        if hook:
            if asyncio.iscoroutinefunction(hook):
                return await hook(*args)
            else:
                return hook(*args)
        return args[0] if args else None

    def update_user_agent(self, user_agent: str):
        self.user_agent = user_agent

    def set_custom_headers(self, headers: Dict[str, str]):
        self.headers = headers

    async def kill_session(self, session_id: str):
        if session_id in self.sessions:
            context, page, _ = self.sessions[session_id]
            await page.close()
            await context.close()
            del self.sessions[session_id]

    def _cleanup_expired_sessions(self):
        current_time = time.time()
        expired_sessions = [
            sid for sid, (_, _, last_used) in self.sessions.items() 
            if current_time - last_used > self.session_ttl
        ]
        for sid in expired_sessions:
            asyncio.create_task(self.kill_session(sid))
            
    async def smart_wait(self, page: Page, wait_for: str, timeout: float = 30000):
        wait_for = wait_for.strip()
        
        if wait_for.startswith('js:'):
            # Explicitly specified JavaScript
            js_code = wait_for[3:].strip()
            return await self.csp_compliant_wait(page, js_code, timeout)
        elif wait_for.startswith('css:'):
            # Explicitly specified CSS selector
            css_selector = wait_for[4:].strip()
            try:
                await page.wait_for_selector(css_selector, timeout=timeout)
            except Error as e:
                if 'Timeout' in str(e):
                    raise TimeoutError(f"Timeout after {timeout}ms waiting for selector '{css_selector}'")
                else:
                    raise ValueError(f"Invalid CSS selector: '{css_selector}'")
        else:
            # Auto-detect based on content
            if wait_for.startswith('()') or wait_for.startswith('function'):
                # It's likely a JavaScript function
                return await self.csp_compliant_wait(page, wait_for, timeout)
            else:
                # Assume it's a CSS selector first
                try:
                    await page.wait_for_selector(wait_for, timeout=timeout)
                except Error as e:
                    if 'Timeout' in str(e):
                        raise TimeoutError(f"Timeout after {timeout}ms waiting for selector '{wait_for}'")
                    else:
                        # If it's not a timeout error, it might be an invalid selector
                        # Let's try to evaluate it as a JavaScript function as a fallback
                        try:
                            return await self.csp_compliant_wait(page, f"() => {{{wait_for}}}", timeout)
                        except Error:
                            raise ValueError(f"Invalid wait_for parameter: '{wait_for}'. "
                                             "It should be either a valid CSS selector, a JavaScript function, "
                                             "or explicitly prefixed with 'js:' or 'css:'.")
    
    async def csp_compliant_wait(self, page: Page, user_wait_function: str, timeout: float = 30000):
        wrapper_js = f"""
        async () => {{
            const userFunction = {user_wait_function};
            const startTime = Date.now();
            while (true) {{
                if (await userFunction()) {{
                    return true;
                }}
                if (Date.now() - startTime > {timeout}) {{
                    throw new Error('Timeout waiting for condition');
                }}
                await new Promise(resolve => setTimeout(resolve, 100));
            }}
        }}
        """
        
        try:
            await page.evaluate(wrapper_js)
        except TimeoutError:
            raise TimeoutError(f"Timeout after {timeout}ms waiting for condition")
        except Exception as e:
            raise RuntimeError(f"Error in wait condition: {str(e)}")

    async def process_iframes(self, page):
        # Find all iframes
        iframes = await page.query_selector_all('iframe')
        
        for i, iframe in enumerate(iframes):
            try:
                # Add a unique identifier to the iframe
                await iframe.evaluate(f'(element) => element.id = "iframe-{i}"')
                
                # Get the frame associated with this iframe
                frame = await iframe.content_frame()
                
                if frame:
                    # Wait for the frame to load
                    await frame.wait_for_load_state('load', timeout=30000)  # 30 seconds timeout
                    
                    # Extract the content of the iframe's body
                    iframe_content = await frame.evaluate('() => document.body.innerHTML')
                    
                    # Generate a unique class name for this iframe
                    class_name = f'extracted-iframe-content-{i}'
                    
                    # Replace the iframe with a div containing the extracted content
                    _iframe = iframe_content.replace('`', '\\`')
                    await page.evaluate(f"""
                        () => {{
                            const iframe = document.getElementById('iframe-{i}');
                            const div = document.createElement('div');
                            div.innerHTML = `{_iframe}`;
                            div.className = '{class_name}';
                            iframe.replaceWith(div);
                        }}
                    """)
                else:
                    print(f"Warning: Could not access content frame for iframe {i}")
            except Exception as e:
                print(f"Error processing iframe {i}: {str(e)}")

        # Return the page object
        return page  
    
    async def crawl(self, url: str, **kwargs) -> AsyncCrawlResponse:
        response_headers = {}
        status_code = None
        
        self._cleanup_expired_sessions()
        session_id = kwargs.get("session_id")
        if session_id:
            context, page, _ = self.sessions.get(session_id, (None, None, None))
            if not context:
                context = await self.browser.new_context(
                    user_agent=self.user_agent,
                    viewport={"width": 1920, "height": 1080},
                    proxy={"server": self.proxy} if self.proxy else None
                )
                await context.set_extra_http_headers(self.headers)
                page = await context.new_page()
                self.sessions[session_id] = (context, page, time.time())
        else:
            context = await self.browser.new_context(
                user_agent=self.user_agent,
                viewport={"width": 1920, "height": 1080},
                proxy={"server": self.proxy} if self.proxy else None
            )
            await context.set_extra_http_headers(self.headers)
            
            if kwargs.get("override_navigator", False):
                # Inject scripts to override navigator properties
                await context.add_init_script("""
                    // Pass the Permissions Test.
                    const originalQuery = window.navigator.permissions.query;
                    window.navigator.permissions.query = (parameters) => (
                        parameters.name === 'notifications' ?
                            Promise.resolve({ state: Notification.permission }) :
                            originalQuery(parameters)
                    );
                    Object.defineProperty(navigator, 'webdriver', {
                        get: () => undefined
                    });
                    window.navigator.chrome = {
                        runtime: {},
                        // Add other properties if necessary
                    };
                    Object.defineProperty(navigator, 'plugins', {
                        get: () => [1, 2, 3, 4, 5],
                    });
                    Object.defineProperty(navigator, 'languages', {
                        get: () => ['en-US', 'en'],
                    });
                    Object.defineProperty(document, 'hidden', {
                        get: () => false
                    });
                    Object.defineProperty(document, 'visibilityState', {
                        get: () => 'visible'
                    });
                """)
            
            page = await context.new_page()

        try:
            if self.verbose:
                print(f"[LOG] 🕸️ Crawling {url} using AsyncPlaywrightCrawlerStrategy...")

            if self.use_cached_html:
                cache_file_path = os.path.join(
                    Path.home(), ".crawl4ai", "cache", hashlib.md5(url.encode()).hexdigest()
                )
                if os.path.exists(cache_file_path):
                    html = ""
                    with open(cache_file_path, "r") as f:
                        html = f.read()
                    # retrieve response headers and status code from cache
                    with open(cache_file_path + ".meta", "r") as f:
                        meta = json.load(f)
                        response_headers = meta.get("response_headers", {})
                        status_code = meta.get("status_code")
                    response = AsyncCrawlResponse(
                        html=html, response_headers=response_headers, status_code=status_code
                    )
                    return response

            if not kwargs.get("js_only", False):
                await self.execute_hook('before_goto', page)
                
                response = await page.goto("about:blank")
                await stealth_async(page)
                response = await page.goto(
                    url, wait_until="domcontentloaded", timeout=kwargs.get("page_timeout", 60000)
                )
                
                # await stealth_async(page)
                # response = await page.goto("about:blank")
                # await stealth_async(page)
                # await page.evaluate(f"window.location.href = '{url}'")
                
                await self.execute_hook('after_goto', page)
                
                # Get status code and headers
                status_code = response.status
                response_headers = response.headers
            else:
                status_code = 200
                response_headers = {}

            await page.wait_for_selector('body')
            await page.evaluate("window.scrollTo(0, document.body.scrollHeight)")

            js_code = kwargs.get("js_code", kwargs.get("js", self.js_code))
            if js_code:
                if isinstance(js_code, str):
                    await page.evaluate(js_code)
                elif isinstance(js_code, list):
                    for js in js_code:
                        await page.evaluate(js)
                
                await page.wait_for_load_state('networkidle')
                # Check for on execution event
                await self.execute_hook('on_execution_started', page)
                
            if kwargs.get("simulate_user", False):
                # Simulate user interactions
                await page.mouse.move(100, 100)
                await page.mouse.down()
                await page.mouse.up()
                await page.keyboard.press('ArrowDown')

            # Handle the wait_for parameter
            wait_for = kwargs.get("wait_for")
            if wait_for:
                try:
                    await self.smart_wait(page, wait_for, timeout=kwargs.get("page_timeout", 60000))
                except Exception as e:
                    raise RuntimeError(f"Wait condition failed: {str(e)}")


            
            # Update image dimensions
            update_image_dimensions_js = """
            () => {
                return new Promise((resolve) => {
                    const filterImage = (img) => {
                        // Filter out images that are too small
                        if (img.width < 100 && img.height < 100) return false;
                        
                        // Filter out images that are not visible
                        const rect = img.getBoundingClientRect();
                        if (rect.width === 0 || rect.height === 0) return false;
                        
                        // Filter out images with certain class names (e.g., icons, thumbnails)
                        if (img.classList.contains('icon') || img.classList.contains('thumbnail')) return false;
                        
                        // Filter out images with certain patterns in their src (e.g., placeholder images)
                        if (img.src.includes('placeholder') || img.src.includes('icon')) return false;
                        
                        return true;
                    };

                    const images = Array.from(document.querySelectorAll('img')).filter(filterImage);
                    let imagesLeft = images.length;
                    
                    if (imagesLeft === 0) {
                        resolve();
                        return;
                    }

                    const checkImage = (img) => {
                        if (img.complete && img.naturalWidth !== 0) {
                            img.setAttribute('width', img.naturalWidth);
                            img.setAttribute('height', img.naturalHeight);
                            imagesLeft--;
                            if (imagesLeft === 0) resolve();
                        }
                    };

                    images.forEach(img => {
                        checkImage(img);
                        if (!img.complete) {
                            img.onload = () => {
                                checkImage(img);
                            };
                            img.onerror = () => {
                                imagesLeft--;
                                if (imagesLeft === 0) resolve();
                            };
                        }
                    });

                    // Fallback timeout of 5 seconds
                    setTimeout(() => resolve(), 5000);
                });
            }
            """
            await page.evaluate(update_image_dimensions_js)

            # Wait a bit for any onload events to complete
            await page.wait_for_timeout(100)

            # Process iframes
            if kwargs.get("process_iframes", False):
                page = await self.process_iframes(page)
            
            await self.execute_hook('before_retrieve_html', page)
            # Check if delay_before_return_html is set then wait for that time
            delay_before_return_html = kwargs.get("delay_before_return_html")
            if delay_before_return_html:
                await asyncio.sleep(delay_before_return_html)
                
            html = await page.content()
            await self.execute_hook('before_return_html', page, html)
            
            # Check if kwargs has screenshot=True then take screenshot
            screenshot_data = None
            if kwargs.get("screenshot"):
                screenshot_data = await self.take_screenshot(url)            

            if self.verbose:
                print(f"[LOG] ✅ Crawled {url} successfully!")

            if self.use_cached_html:
                cache_file_path = os.path.join(
                    Path.home(), ".crawl4ai", "cache", hashlib.md5(url.encode()).hexdigest()
                )
                with open(cache_file_path, "w", encoding="utf-8") as f:
                    f.write(html)
                # store response headers and status code in cache
                with open(cache_file_path + ".meta", "w", encoding="utf-8") as f:
                    json.dump({
                        "response_headers": response_headers,
                        "status_code": status_code
                    }, f)

            async def get_delayed_content(delay: float = 5.0) -> str:
                if self.verbose:
                    print(f"[LOG] Waiting for {delay} seconds before retrieving content for {url}")
                await asyncio.sleep(delay)
                return await page.content()
                
            response = AsyncCrawlResponse(
                html=html, 
                response_headers=response_headers, 
                status_code=status_code,
                screenshot=screenshot_data,
                get_delayed_content=get_delayed_content
            )
            return response
        except Error as e:
            raise Error(f"Failed to crawl {url}: {str(e)}")
        finally:
            if not session_id:
                await page.close()
                await context.close()

    async def crawl_many(self, urls: List[str], **kwargs) -> List[AsyncCrawlResponse]:
        semaphore_count = kwargs.get('semaphore_count', 5)  # Adjust as needed
        semaphore = asyncio.Semaphore(semaphore_count)

        async def crawl_with_semaphore(url):
            async with semaphore:
                return await self.crawl(url, **kwargs)

        tasks = [crawl_with_semaphore(url) for url in urls]
        results = await asyncio.gather(*tasks, return_exceptions=True)
        return [result if not isinstance(result, Exception) else str(result) for result in results]

    async def take_screenshot(self, url: str, wait_time=1000) -> str:
        async with await self.browser.new_context(user_agent=self.user_agent) as context:
            page = await context.new_page()
            try:
                await page.goto(url, wait_until="domcontentloaded", timeout=30000)
                # Wait for a specified time (default is 1 second)
                await page.wait_for_timeout(wait_time)
                screenshot = await page.screenshot(full_page=True)
                return base64.b64encode(screenshot).decode('utf-8')
            except Exception as e:
                error_message = f"Failed to take screenshot: {str(e)}"
                print(error_message)

                # Generate an error image
                img = Image.new('RGB', (800, 600), color='black')
                draw = ImageDraw.Draw(img)
                font = ImageFont.load_default()
                draw.text((10, 10), error_message, fill=(255, 255, 255), font=font)
                
                buffered = BytesIO()
                img.save(buffered, format="JPEG")
                return base64.b64encode(buffered.getvalue()).decode('utf-8')
            finally:
                await page.close()

